Kiln Pointers

A quick sketch in a kiln log book can show shelf placement, cones, the position of ware on the shelf, etc.

CONTENTS

Finding a Kiln’s “Sweet Spot”

Recent Q&As: 3-zone kilns; adding insulation to the top and bottom; deciding between the SC-2 and FireFly

A Kiln Story: The Kiln That Survived a Hurricane

Memorable Quote

News: Paragon’s Electricity Goes Green

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FINDING A KILN’S “SWEET SPOT”

As with an expert carpenter who has mastered a tool or a photographer who has mastered a camera, the expert kiln operator has a precise “feel” for the kiln. Results are consistent.

How do you gain a “feel” for a kiln? Maggie Furtak of Malden, Massachusetts, gives the best answer I have read. She writes as a potter, but her basic idea applies to all the firing arts:

“Take careful notes on each firing,” Maggie explained. “Every kiln has a sweet spot, an ideal set-up. For mine it is best started at 6:00 a.m. for the best voltage, and never on a weekend or holiday, or when the temperature outside is above 90 degrees F or below 30 degrees F. Otherwise the neighbors’ heat and AC and giant TVs steal my power, even if I turn my heat and AC off, and it's hard to get the kiln to temperature.

“There will also be an ideal set-up of shelves for your kiln,” Maggie continued. “Take notes on how you place the shelves for each glaze firing, and how the pyrometric cones on each shelf ended up. You will generally need a taller shelf on the bottom to get an even firing, but how tall? Take notes of how tall the posts are for each level.

“If you have a good kiln log right from the start, you'll be able to learn the quirks of your particular kiln and get consistent firings a lot faster than if you rely on gut intuition and memory. You'll have a good idea of when to shut off your kiln. And if you wonder if you can get away with something a year from now, you'll be able to look back at your notes and see what happened last time you tried it.”

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RECENT Q&As

Q. My digital kiln has 3 zones with 3 thermocouples. The kiln stalls out and shows an error code. Suggestions?

A. The back of the controller has a series of terminals for the thermocouples. One set of terminals is for the top thermocouple, another set is for the center thermocouple, and the third set of terminals is for the bottom thermocouple.

If the thermocouples are connected to the wrong terminals on the back of the controller, the relays and elements will add heat to the wrong sections of the kiln. This will cause the kiln to stall.

To check that the thermocouples are connected to the correct terminals, compare the back of the controller with a wiring diagram for your kiln model.

Q. Would there be anything wrong if I were to put my kiln on an old kiln bottom and put the old kiln lid on top of my kiln for extra insulation?

A. A spare firebrick bottom between the kiln and kiln stand and a spare lid on top of your kiln will add to the insulation. This may save electricity.

Q. I am trying to decide between the SC-3 and the FireFly. I make jewelry out of dichoic glass and PMC clay. Any suggestions?

A. The SC-3 is faster than the FireFly, but the FireFly is rated to 2350F, while the SC-3 is rated to 2000F. The SC-3 optional window gives a better view of the interior than the FireFly window. This is because the SC-3 window is to the side of the interior, while the FireFly window is above the interior. Glass is easier to see in profile than from above.

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A KILN STORY: THE KILN THAT SURVIVED A HURRICANE

Janet Harriman wrote, “I have a kiln story for you. I had a group of students in Hatteras, North Carolina who purchased a Paragon E9-AX from Thompson Enamel with the non-digital pyrometers for enameling. After a hurricane, the studio and all the tools washed away. The students found the kiln, and it was still working.”

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MEMORABLE QUOTE

"Laughter is the most healthful exertion." --Christoph Wilhelm Hufeland

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NEWS: PARAGON’S ELECTRICITY GOES GREEN

Since last month, Paragon has been using an energy provider that produces a portion of its electricity on wind farms in Texas rather than through the use of fossil fuels alone. What does this mean? The use of pollution-free 100% renewable energy is created from natural resources that will never run out and helps preserve our environment for future generations! --Kelly Bartholomew

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In the hands of an expert, driving a car or firing a kiln becomes an art form. Bicycles are another example. When I lived in Libya as a teenager, I saw Arabs riding their bicycles to Tripoli with hands in their pockets. That was a common sight on cold winter mornings.